Flanking rudder control



Nov. 21, 1961 C. R. HORTON, JR

F LANKING RUDDER CONTROL u INVENTOR. Clan/rase R. Horton Jr.

Nov. 21, 1961 c. R. HoRToN, JR

FLANKING RUDDER CONTROL 2 Sheets-Sheet 2 Filed May 16, 1955 STEERING ENGINE FIG. E

FIG. 5

INVENToR. Clarence R. Horon Jr.

Unite States are This invention relates generally to steering rudders for push tow boats and more specifically to new and useful astern steering or flanking rudders for increasing the maneuverability of the boat when the propellers are reversed with a minimum or complete absence of impedance to normal forward propulsion of the boat.

The principal object of the invention is to improve the maneuverability of a push tow type of boat handling a long string of barges when the boat propellers are reversed.

Another object of the invention is to provide a novel method of mounting and operating the flanking rudders so as to minimize the existing detrimental effect of these rudders upon efficiency of forward propulsion of the boat and provide the maximum astern steering by positioning each such rudder at its optimum angle in hard down position.

A further object of the invention is to provide a novel mechanism for operating such flanking rudders so as to obtain the maximum benefits therefrom in maneuverability of the boat.

Propeller driven river boats of the push tow type handling long strings of barges have long felt the need for additional maneuverability in negotiating winding rivers, locking, and positioning their tow at docks. The use of so-called flanking rudders mounted forwardly of the propellers for this purpose is known. The practice of mounting the propellers within tunnels beneath the boat for the same purpose is also known. The Kort nozzle is one of the most successful propulsion devices, and the use of flanking rudders with the Kort nozzle is also known. Heretofore none of these flanking rudder systems have provided the maximum dmired astern steering.

The term astern steering as used herein refers to reversing the propeller so as to force Water forwardly of the boat against the flanking rudders for securing lateral control forces. By reason of the flanking rudders being mounted forwardly of the propeller, these rudders tend to impede forward propulsion of the boat unless the rudders are properly angled to conform to the actual flow of the water converging toward the propeller. The maximum effect on steering when the flanking rudders are in hard down position can only be obtained when both flanking rudders are disposed so as to offer maximum uniform turning of the water flowing from the reversed propeller to the flanking rudders.

After an extended series of tests l have determined that the optimum angle of the flanking rudder relative to the water flowing towards the propeller varies with the loading on the propeller and with the speed of the boat. For maximum eflciency the flanking rudder is pivoted to the boat intermediate its ends and the minimum of impedance to propulsion from these rudders results when the forward edges of the rudders at opposite sides of the propeller are toed outwardly to the proper angle. Since it is preferable to move both of the rudders of a pair simultaneously, the usual method is to connect the tillers of each pair of rudders by a link thus securing equal movement of the rudders to hard down position at either side of the propeller. When the rudders, so connected, are angled relative to each other as above described, movement of one rudder to optimum hard down position leaves the other rudder of the pair at a different 'lee hard down angle since each must move a different distance to reach the same final position. As a result of such condition, the steering effect from each rudder of the pair of rudders was different since both were never at the sarne optimum angle for effective steering.

In the present invention I have overcome this condition by providing a differential linkage which moves the rudders of each pair at a different rate so that in any selected hard down position both rudders offer the same angle to the water flowing towards them from the reversed propeller. In other words, a single steering engine moving in one direction or the other turns both flanking rudders of the pair from a toe out relation to a parallel or other suitable relation when in hard down position to secure maximum steering efllciency. I have mounted the rudders as close as practical to the propeller or Kort nozzle to further increase their efficiency. In the tests referred to l have obtained 25% or more increased efficiency over present practices by my method of mounting and operating the flanking rudders.

v ln the drawings forming part of this disclosure,

FIG. l shows in plan a schematic arrangement of the flanking rudders and one form of linkage and steering engine;

FIG. 2 shows in plan one pair of the flanking rudders and associated propeller, Kort nozzle and steering rudder of FIG. l;

FIG. 3 is a plan View of a schematic arrangement of a modified form of linkage and steering engine;

FIG. 4 shows in plan view deails of construction of the linkage arrangement of FIG. 3 which is symmetrical about the transverse center line;

. FIG. 5 shows a section through the steering engine at lines V-V of FIG. 4; and

FIG. 6 shows a Section on lines VI-VI of FIG. 4 illustrating one form of flanking rudder.

Referring now to FIGS. l and 2 of the drawings, it will be understood that the flanking rudders and Kort nozzle shown therein are mounted on the boat in any well known suitable manner, and the boat has been omitted since its construction forms no part of the present invention. The Kort nozzle 1 of suitable well known design customarily has a forward flange 2 and aft flange 3 providing bottom pivotal connections for the flanging and steering rudders respectively. The nozzle 1 is shown in cross section for purposes of clarity. The propeller 4 and propeller shaft 5 may also be of lany suitable design depending upon the boat to be propelled thereby as may the stern rudder 20.

The flanking rudders 6 and 6a arranged in pairs about the propeller shaft forward of the propeller 4 are each provided with a stem 7 having one end pivotally mounted in nozzle flange 2 and the upper end supported on the boat deck (not shown). The stems 7 of rudders 6 at opposite sides of the center line of the boat (FIG. 2) have tillers 8 mounted thereon above the boat deck (not shown) and are connected by the rods 9. Each rod 9 has one end pivotally connected to its respective tiller 8 at 10, and the opposite end having a common connection 11 with the steering engine 12. The steering engine may be of any suitable design and is actuated by any suitable control means, preferably hydraulic. A differential linkage arm 13 extends outward from rudder 6 and a similar arm 14 from rudder 6a, both arms 13 and 14 being mounted at one end on the stem 7 of their respective rudders and connected at the opposite ends by a tie rod 15 having pivotal connections 16 therewith.

As shown in FIGS. l and 2 the pairs of flanking rudders 6 and 6a are toed out forwardly and toed in a corresponding amount aft about lines A and B through the stems of rudders 6 of the respective pairs and parallel to the longitudinal center line of the boat. TheV angularity of the rudders is shown as being 5 which for the particular design of rudder, loading on the propeller and boat speed provides the optimum angle for minimum impedance by these flanking rudders to the flow of water to the propellers. When the forward ends of rudders 6, of each pair, are moved to the left by the rods 9, upon actuation of steering engine 12, to a hard down position of 40 relative to line A and B, it will be obvious that rudders 6 rotated upon their stems 7 through an angle of 35. This results from rudders 6 being initially toed out 5. Each rudder 6a, however, being toed out 5 from the line B must move through an angle of 45 in order to be parallel with the associated rudder 6. The differential linkage 13, 14 and 15 being actuated by the stems 7 of rudders 6 accomplishes this result. Conversely when the outer ends of rudders 6, of each pair of rudders, are moved to a hard down position of 40 to the right of line A, the associated rudders 6a move through an angle of 35 and rudders 6 move through an angle of 45. This angular differential is obtained by the differential linkage 13, 14 and 15 to bring both rudders 6 and 6a of each pair in parallel relation in hard down position.

The function of the flanking rudders is to steer the boat and tow when the propellers are reversed. This is accomplished by the flanking rudders deflecting the Water moving from the reversed propellers toward the flanking rudders. The maximum deflection of water occurs when both rudders 6 and 6a are at the same optimum angularity to the flow of the water. This relation is referred to herein as being parallel. Due to the rudders of each pair being normally toed out fo1wardly of their propeller, the rudders of each pair must move through a different are of rotation in passing from normal toed out relation to so-called parallel relation when in hard down position. If both rudders of each pair were directly connected to their respective rods 9 this condition could not be obtained since each rudder would have the same angular movement. The members 13 and 14 of the differential linkage are shown as being toed in 10 from the lines A and B to bring rudders 6 and 6a in parallel relation when in 40 hard down position. This angle of toe in of members 13 and 14 may be varied to secure the optimum steering efficiency when the design of rudders is modified. Since rudders 6 are moved through a different angular distance when in hard down position on opposite sides of lines A, the steering engine is designed to move rods l9 a greater distance to the right than to the left as the rudders 6 move a respectively greater or lesser angu lar distance to hard down position.

An alternate form of differential linkage is shown in FIGS. 3 to 6 inclusive of the drawings. In these figures the rudders 106 and 106e are also toed out forward and toed in aft as in FIGS. 1 and 2. Due to the specific design of the rudders the toe out forward of the rudder stems 107 is greater than the toe in aft thereof. The portions of each rudder aft of their stems 107 are toed in 5, as in FIGS. l and 2, and in hard down position are disposed 40 on opposite sides of the lines A and B through rudders 106 and 106a respectively. The stem 107 of rudder 106 has a tiller 113 mounted thereon and stem 107 of rudder 106e has a tiller 114 mounted thereon. Tillers 113 and 114 forward of the posts toeing in about 10. A tie rod 115 has a pivotal connection 116 at each end thereof to the tillers 113 and 114 of each pair of rudders. A steering engine 112 has a cross head 117 thereon to which are pivotally connected at 118 the tie rods 109 which extend therefrom to the adjacent tillers 113 and 114. The steering engine comprises a base formed of spaced channels 119 mounted on the boat deck 120, a portion of which is shown in FIG. 5 only. Disposed between channels 119 adjacent each end thereof are the cylinders 121 having a common piston 122 mounted therein. The cross head 117 is mounted on the piston 122 and is supported upon the rollers 123 thereof engaging the top flanges of the channels 119.

The piston 122 moves cross head 117 an equal distance to opposite sides of the neutral position shown in FIG. 4. The cylinders 121 are supported on channels 119 by suitable brackets 124 secured to channels 119. The outer ends of cylinders 121 have suitable conduits (not shown) connected thereto for selective admission of hydraulic pressure to actuate the piston 122.

Referring now to FIGS. 3 and 4, the arrangement shown herein may be referred to as a double differential system of linkage in that the steering engine 112 having a uniform length of stroke to hard down positions of the opposite pairs of flanking rudders effects a different linear movement of each rudder tiller directly connected therewith when moving in one direction from neutral position than when moving the same distance in the opposite direction. The steering engine cross head 117 has a common connection to the tie rods 109 extending therefrom to the adjacent tillers 113 and 114 of the rudders at opposite sides of the cross head. The tillers 113 and 114 of each pair of rudders at opposite sides of the cross head are connected by tie rods 115. Movement of cross head 117 a distance S to the right from neutral position as in FIG. 3 moves the pairs of tillers 113, 114 and their associated flanking rudders 106 and 106n from positions shown in full lines to that shown in dotanddash lines, the latter position being hereinbefore referred to as parallel hard down position in which the aft ends of the associated rudders are at an angle of 40 to their respective lines A and B. Correspondingly the rudder 106@ and its associated tiller, connected to the left side of the cross head, in moving to the right, moves a linear distance which is the same as that traveled by rudder 106n and tiller 114 at the far right side of the cross head, but a lesser linear and angular distance than that traveled by the adjacent rudder 106 and associated tiller 113 directly connected with the cross head. The converse movement of each rudder in each pair takes place when the cross head moves to the left from neutral position in FIG. 3.

-A comparison of both of the forms of my invention as disclosed in FIGS. l and 3 shows that each moves the rudders of each pair from an optimum diverging angular relation affording minimum interference to water flowing towards the propellers, to the optimum parallel angular relation affording maximum turning of water flowing from the reversed propeller to the flanking rudders and that the turning of the water flow from the reversed propeller is substantially uniform by each rudder of the pair associated with the respective propeller. The differential linkages disclosed by both forms of the invention are also adjustable so as to secure the required angular relation between rudders in hard down position taking into consideration the loading on the propeller and speed of the boat. Rudder design may also affect the final angular relation of the rudders. ln FIG. 2 the design of rudder permits the same angular toe out forward as the toe in aft. In FIG. 3 optimum steering effect is obtained from the rudders thereof by making the forward toe out of the rudders greater than the toe in aft thereof. The degree of angular movement of the rudders from forward propulsion position to hard down position may be readily varied by relative adjustment between the tillers and rudders during assembly of the linkage. The tie rods 15 and 11S could have turnbuckles or other equivalent means incorporated therein to effect adjustment of the length thereof and of the angular relation between tillers 13, 14 and 113, 114 of each pair of rudders.

The details of construction as used herein were for purposes of illustration and not limitation and it is not my intention to be bound thereby except as made necessary by the scope of the appended claims.

I claim:

1. In a rudder control system for boats having a propeller and a steering rudder disposed rearwardly thereof, the combination of a pair of pivotally mounted lflanking rudders disposed forwardly of the propeller and on opposite sides of the axis `of rotation thereof, pivotally connected means disposed between said pair of anking rudders and having fixed connections with `each rudder providing toe in of the ends of the rudders adjacent the pro peller when the rudders are in neutral position, and substantially parallel alignment of the rudders adjacent the propeller when one of the rudders is moved by said means to a hard down position to either side of the propeller.

2. In a rudder control system for -boats as defined in claim 1, wherein a pair of propellers are disposed transversely of the boat, a pair of flanking rudders are disposed forwardly of each propeller with said pivotally connected means disposed between each said pair of anking rudders, a reciprocatable member extends transversely of the boat between the said pivotally connected means of each pair of rudders and the opposite ends of said member are pivotally connected by a link member to the adjacent each said means, whereby equal reciprocal movement of said member transversely of the boat provides concurrent movement of said pairs of rudders to parallel hard down positions.

3. In a rudder control system `for propeller driven push tow boats having a pair of stern propellers spaced transversely of the boat with their axes of rotation disposed longitudinally of the boat, a pair of flanking rudders disposed forwardly of each propeller and lying on opposite sides of the axis of rotation of the respective propeller, each said anking rudders having an axis of rotation disposed intermediate the ends of the rudder, each said pair of ilanking rudders having their trailing ends disposed in 30 converging relation when in neutral position, a tiller mounted in fixed relation to the axis of rotation of each rudder of each pair for securing concurrent rotation therewith and extending forwardly in converging relation to the adjacent tiller of said pair of rudders, a transverse link pivotally connecting the forward ends of adjacent tillers of each said pairs of tillers, reciprocatable means disposed between said pairs of tillers, and a link member pivotally connecting one of each pair of tillers with said reciprocatable member effecting concurrent movement of said pairs of rudders into parallel hard down positions.

4. fIn a push type tow boat ilanking rudder control mechanism of the character described, in combination, a reversible propeller having its axis of rotation disposed longitudinally of the boat, a anking rudder pivotally mounted at opposite sides of the axis of rotation of said propeller and forwardly of the propeller with the trailing ends of the rudders disposed in an angular relation to each other offering minimum resistance to water flowing therepast to the propeller, a tiller pivotally mounted inxed relation to each said flanking rudder for rotation about the axis of rotation of said rudder and extending forwardly therefrom between the pair of rudders, each of said tillers being of equal length and equally angularly disposed towards the axis of rotation of the propeller, a member pivotally connecting the forward ends of said tillers, and means connected to one of said tillers for selectively moving it in equal opposite directions into a selected hard down position and disposing the trailing ends of the connected rudders in parallel relation,

References Cited in the file of this patent UNITED STATES PATENTS 1,717,286 Ward June 11, 1929 2,030,375 Kort Feb. 11, 1936 2,201,859 4Edwards May 21, 1940 2,559,823 Klose July 10, 1951 UNITED STATES PATENT OEEIOE CERTIFICATE 0E CORRECTION Patent Non MOOQABS l November 21y 1961 Clarence R., HortonV JimJ It is hereby certified that error appears in the above numbered patent requiring Correction and that the said Letters Patent should read as corrected below.

1n the grantv lines 2 and 12 and in the heading to the printed S10ecificationW line 1X1 name of assigneeI for U'Drano COI-poImationv each oecurrence read w Dravo Corporation u; column .2 1ine 30s for Udeai 1s" read details -Q-:g .same co1umn 2 line 44V for "1anging" read -u flanking -m Signed and sealed this 17th day of April 1962,

(SEAL) Attest:

ESTON G JOHNSON i DAVID L. LADD Attesting Ufficer Commissioner of Patents 

